Application of III-Nitride electronic devices is considerably restricted due to a high interface state between III-Nitride material and its passivation layer or gate dielectric. According to research results, it is the interface oxidation in the technical process of III Nitride that leads to the high interface state. Additionally, Low Pressure Chemical Vapor Deposition (LPCVD) technology is a much mature technique for manufacturing film dielectric in CMOS processes. Currently, how to lower down the interface state and thus form high-quality film layers using deposition techniques, such as LPCVD, has become essential in promoting the industrialization of III-Nitride power electronics.